Field of the Invention
The present invention relates to an audio signal processing technique.
Description of the Related Art
There is known a technique of forming a directivity in the direction of a target sound source by filtering using a plurality of microphone elements (microphone array), and separating a sound of the target sound source from acquired audio signals of a plurality of channels. Since it is difficult to narrow the beam width of the directivity, it is also difficult to accurately separate only the target sound source.
According to Japanese Patent Laid-Open No. 2001-204092, an overlapping area of the directivities of two directional microphones is formed, and a common component of two direction sounds obtained with the respective directivities is extracted, thereby obtaining a sound in the overlapping area narrower than the beam width of a single directivity.
However, especially when a target sound source is close to the direction of a non-target sound source, the sound source separation performance according to the conventional technique is still unsatisfactory, and it is desired to improve directivity control.